Multi-channel satellite signal receiving apparatus

ABSTRACT

A multi-channel satellite signal receiving apparatus is capable of simultaneously providing broadcast programs from a plurality of different sets of transponders in a satellite broadcast system. According to an exemplary embodiment, the multi-channel satellite signal receiving apparatus includes an input operative to receive input signals via a single cable from a predetermined frequency band having a first sub-band and a second sub-band. The first sub-band includes first signals which previously exhibited a first polarization provided from a first set of transponders, and the second sub-band includes second signals which previously exhibited a second polarization provided from a second set of transponders. Signal processing circuitry is operative to simultaneously provide a plurality of digital transport streams corresponding to the first and second sets of transponders responsive to the first and second signals.

The present invention generally relates to multi-channel signalreceivers, and more particularly, to a multi-channel satellite signalreceiving apparatus which is capable of simultaneously providingbroadcast programs from a plurality of different sets of transponders ina satellite broadcast system.

In a satellite broadcast system, a satellite receives signalsrepresenting audio, video, and/or data information from an earth-basedtransmitter. The satellite amplifies and rebroadcasts these signals to aplurality of satellite signal receivers, located at the residences ofconsumers, via transponders operating at specified frequencies andhaving given bandwidths. Such a system includes an uplink transmittingportion (i.e., earth to satellite), an earth-orbiting satellite signalreceiving and transmitting unit, and a downlink portion (i.e., satelliteto earth) including one or more satellite signal receivers located atthe residences of consumers.

At least one existing satellite broadcast system operates in a mannersuch that a first set of transponders apply a first polarization (e.g.,right hand circular polarization) to the signals broadcast from itstransponders, while a second set of transponders apply a second andopposite polarization (e.g., left hand circular polarization) to thesignals broadcast from its transponders. With current satellite signalreceivers, a problem exists in that a given satellite signal receiver isunable to simultaneously receive signals from both the first and secondsets of transponders. In particular, a typical satellite antenna systememploys a low noise block converter (LNB) which selectively providesbroadcast signals to a given satellite signal receiver from either thefirst set of transponders, or the second set of transponders, but notboth sets of transponders at the same time. Accordingly, the givensatellite signal receiver cannot access broadcast programs provided fromboth sets of transponders at the same time. As a result, if a userprovides a channel change command to switch from a broadcast programprovided from the first set of transponders to another broadcast programprovided from the second set of transponders, the given satellite signalreceiver must switch the LNB between the first and second sets oftransponders, which may in turn increase channel change times. Anotherkey problem with such satellite signal receivers is that users cannotwatch a broadcast program provided from the first set of transponders,and simultaneously record another broadcast program provided from thesecond set of transponders. One common approach to addressing theforegoing problems is to simply run two cables (i.e., one for each setof transponders) from the LNB to the satellite signal receiver. Thisapproach, however, tends to be impractical and costly for the user, andis therefore not desirable.

Accordingly, there is a need for a multi-channel satellite signalreceiving apparatus which avoids the foregoing problems, and alsosimultaneously provides broadcast programs from a plurality of differentsets of transponders in a satellite broadcast system.

In accordance with an aspect of the present invention, a multi-channelreceiving apparatus is disclosed. According to an exemplary embodiment,the multi-channel receiving apparatus comprises input means forreceiving input signals via a single cable from a predeterminedfrequency band having a first sub-band and a second sub-band. The firstsub-band includes first signals which previously exhibited a firstpolarization provided from a first set of transponders, and the secondsub-band includes second signals which previously exhibited a secondpolarization provided from a second set of transponders. Processingmeans simultaneously provide a plurality of digital transport streamscorresponding to the first and second sets of transponders responsive tothe first and second signals.

In accordance with another aspect of the present invention, a method foroperating a multi-channel satellite signal receiving apparatus isdisclosed. According to an exemplary embodiment, the method comprisessteps of receiving input signals via a single cable from a predeterminedfrequency band having a first sub-band and a second sub-band. The firstsub-band includes first signals which previously exhibited a firstpolarization provided from a first set of transponders, and the secondsub-band includes second signals which previously exhibited a secondpolarization provided from a second set of transponders. The first andsecond signals are processed to simultaneously provide a plurality ofdigital transport streams corresponding to the first and second sets oftransponders.

The above-mentioned and other features and advantages of this invention,and the manner of attaining them, will become more apparent and theinvention will be better understood by reference to the followingdescription of embodiments of the invention taken in conjunction withthe accompanying drawings, wherein:

FIG. 1 is a block diagram of a multi-channel satellite signal receivingapparatus according to an exemplary embodiment of the present invention;

FIG. 2 is a block diagram of a multi-channel satellite signal receivingapparatus according to another exemplary embodiment of the presentinvention; and

FIG. 3 is a flowchart illustrating steps according to an exemplaryembodiment of the present invention.

The exemplifications set out herein illustrate preferred embodiments ofthe invention, and such exemplifications are not to be construed aslimiting the scope of the invention in any manner.

Referring now to the drawings, and more particularly to FIG. 1, a blockdiagram of a multi-channel satellite signal receiving apparatus 100according to an exemplary embodiment of the present invention is shown.As shown in FIG. 1, multi-channel satellite signal receiving apparatus100 comprises input means such as input block 10, and processing meanssuch as signal processing circuitry 20 to 70. Signal processingcircuitry 20 to 70 includes first filtering means such as high passfilter (HPF) 20, second filtering means such as low pass filter (LPF)30, first analog-to-digital (A/D) converting means such as first A/Dconverter 40, second A/D converting means such as second A/D converter50, digital signal processing means such as digital signal processing(DSP) tuners 60, and transport processing means such as transportprocessor 70. The foregoing elements of FIG. 1 may be embodied usingintegrated circuits (ICs), and any given element may for example beincluded on one or more ICs. For clarity of description, certainconventional elements associated with multi-channel satellite signalreceiving apparatus 100 such as certain control signals, power signalsand/or other elements may not be shown in FIG. 1.

Input block 10 is operative to receive input signals from an LNB of anoutdoor unit via a single cable, such as an RG-6 type coaxial cable,and/or other type of cable. According to an exemplary embodiment, theinput signals received by input block 10 occupy a predeterminedfrequency band of 950 to 2150 MHz and include first signals in a firstsub-band from 950 to 1450 MHz and second signals in a second sub-bandfrom 1650 to 2150 MHz. According to this exemplary embodiment, the firstsignals in the first sub-band previously exhibited a first polarization(e.g., right hand circular polarization) provided from a first set oftransponders, and the second signals in the second sub-band previouslyexhibited a second polarization (e.g., left hand circular polarization)provided from a second set of transponders. The LNB of the outdoor unitprocesses the first and second signals as provided by the first andsecond sets of transponders in order to place them in the first andsecond sub-bands, respectively. Also according to this exemplaryembodiment, there are a total of 32 transponders and the first set oftransponders includes odd numbered transponders (e.g., 1, 3, 5 . . .31), while the second set of transponders includes even numberedtransponders (e.g., 2, 4, 6 . . . 32). In practice, however, the totalnumber of transponders may differ. The first and second sets oftransponders referred to herein may for example represent all, orsubstantially all, of the transponders operating in a given satellitebroadcast system, which may include one or more satellites. Input block10 may also be operative to perform certain known processing operations,such as signal amplification, automatic gain control, filtering and/orother operations.

HPF 20 is operative to perform a high pass filtering operation tothereby separate the first and second sub-bands. According to anexemplary embodiment, HPF 20 is operative to pass signals having afrequency greater than 1550 MHz. Accordingly, HPF 20 passes signals fromthe second sub-band (e.g., 1650 to 2150 MHz), while blocking signalsfrom the first sub-band (e.g., 950 to 1450 MHz). LPF 30 is operative toperform a low pass filtering operation to also separate the first andsecond sub-bands. According to an exemplary embodiment, LPF 30 isoperative to pass signals having a frequency less than 1550 MHz.Accordingly, LPF 30 passes signals from the first sub-band (e.g., 950 to1450 MHz), while blocking signals from the second sub-band (e.g., 1650to 2150 MHz).

First A/D converter 40 is operative to convert the signals provided fromHPF 20 from an analog format to a digital format, thereby generatingdigital signals from the second sub-band. Second A/D converter 50 isoperative to digitize the signals provided from LPF 30 from an analogformat to a digital format, thereby generating digital signals from thefirst sub-band. According to an exemplary embodiment, a common clock(CLK) controls first and second A/D converters 40 and 50. Also accordingto an exemplary embodiment, the common clock (CLK) exhibits a frequencywhich is between the first and second sub-bands. For example, the commonclock (CLK) may exhibit a frequency of 1550 MHz. As indicated in FIG. 1,first and second A/D converters 40 and 50 each operate on differentedges of the common clock (CLK). Although not expressly shown in FIG. 1,a multiplexer may be added to receive the digital signals provided fromfirst and second A/D converters 40 and 50 in order to combine thedigital signals into a single digital stream.

DSP tuners 60 are operative to process the digital signals provided fromfirst and second A/D converters 40 and 50 to thereby generate aplurality of digitally processed signal streams in a simultaneousmanner. According to an exemplary embodiment, DSP tuners 60 areoperative to perform various processing functions including digitaltuning (e.g., multi-channel frequency downconversion), digitalfiltering, decimation, digital demodulation (e.g., Quadrature PhaseShift Keyed (QPSK), Quadrature Amplitude Modulation (QAM), and/or othertypes of demodulation), and Forward Error Correction (FEC) decodingfunctions. Also according to an exemplary embodiment, DSP tuners 60operate on both edges of the common clock (CLK), and thereby exhibittwice the processing speed of first and second A/D converters 40 and 50.According to this exemplary embodiment, each of the digitally processedsignal streams provided from DSP tuners 60 corresponds to a giventransponder, and may include a plurality of time-division multiplexedbroadcast programs.

Transport processor 70 is operative to process the digitally processedsignal streams provided from DSP tuners 60 to thereby generate andoutput a plurality of digital transport streams in a simultaneousmanner. As previously indicated herein, each of the digitally processedsignal streams provided from DSP tuners 60 corresponds to a giventransponder. Accordingly, with a satellite broadcast system having atotal of 32 transponders, transport processor 70 will receive 32different digitally processed signal streams as inputs. According to anexemplary embodiment, transport processor 70 demultiplexes thesedigitally processed signal streams into a plurality of digital transportstreams which each includes a broadcast program. In this manner,broadcast programs provided from both the first and second sets oftransponders may be accessed in a simultaneous manner. Although notexpressly shown in FIG. 1, transport processor 70 may include an inputselect function which enables one or more of the digital transportstreams to be selectively output. As indicated in FIG. 1, the digitaltransport streams output from transport processor 70 may be provided forfurther processing (e.g., digital decoding, etc.), and/or may berebroadcast to one or more other devices.

FIG. 2 shows a block diagram of a multi-channel satellite signalreceiving apparatus 200 according to another exemplary embodiment of thepresent invention. As indicated in FIG. 2, multi-channel satellitesignal receiving apparatus 200 includes several elements which are thesame as or similar to elements of multi-channel satellite signalreceiving apparatus 100 of FIG. 1, and such elements are represented bythe same reference numbers in both FIGS. 1 and 2. For clarity ofdescription, these common elements will not be described again, and thereader may refer to the description of these elements previouslyprovided herein.

In FIG. 2, multi-channel satellite signal receiving apparatus 200includes two separate DSP tuners 60A and 60B which are operative toprocess the digital signals provided from first and second A/Dconverters 40 and 50, respectively, to thereby generate a plurality ofdigitally processed signal streams in a simultaneous manner. Accordingto an exemplary embodiment, DSP tuners 60A and 60B are each operative toperform various processing functions including digital tuning (e.g.,multi-channel frequency downconversion), digital filtering, decimation,digital demodulation (e.g., QPSK, QAM, and/or other types ofdemodulation), and FEC decoding functions. With the exemplary embodimentof FIG. 2, DSP tuners 60A provide digitally processed signal streamscorresponding to the first set of transponders (e.g., odd numberedtransponders), while DSP tuners 60B provide digitally processed signalstreams corresponding to the second set of transponders (e.g., evennumbered transponders). Also with the exemplary embodiment of FIG. 2,A/D converters 40 and 50 may each operate on the same edge of the commonclock (CLK).

To facilitate a better understanding of the inventive concepts of thepresent invention, an example will now be provided. Referring to FIG. 3,a flowchart 300 illustrating steps according to an exemplary embodimentof the present invention is shown. For purposes of example andexplanation, the steps of FIG. 3 will be described with reference tomulti-channel satellite signal receiving apparatuses 100 and 200 ofFIGS. 1 and 2. The steps of FIG. 3 are merely exemplary, and are notintended to limit the present invention in any manner.

At step 310, multi-channel satellite signal receiving apparatus 100/200receives input signals from the LNB of an outdoor satellite unit.According to an exemplary embodiment, input block 10 receives the inputsignals at step 310 and the received input signals occupy apredetermined frequency band of 950 to 2150 MHz having a first sub-bandfrom 950 to 1450 MHz and a second sub-band from 1650 to 2150 MHz.According to this exemplary embodiment, the first sub-band includesfirst signals which previously exhibited the first polarization (e.g.,right hand circular polarization) provided from the first set oftransponders (e.g., odd numbered transponders), and the second sub-bandincludes second signals which previously exhibited the secondpolarization (e.g., left hand circular polarization) provided from thesecond set of transponders (e.g., even numbered transponders). Aspreviously indicated herein, the first and second sets of transpondersmay for example represent all, or substantially all, of the transpondersoperating in a given satellite broadcast system, which may include oneor more satellites.

At step 320, multi-channel satellite signal receiving apparatus 100/200separates the first and second sub-bands. According to an exemplaryembodiment, HPF 20 and LPF 30 each separate the first and secondsub-bands at step 320 using high pass and low pass filtering operations,respectively. According to this exemplary embodiment, HPF 20 passessignals from the second sub-band (e.g., 1650 to 2150 MHz), whileblocking signals from the first sub-band (e.g., 950 to 1450 MHz), whileLPF 30 passes signals from the first sub-band (e.g., 950 to 1450 MHz),while blocking signals from the second sub-band (e.g., 1650 to 2150MHz).

At step 330, multi-channel satellite signal receiving apparatus 100/200generates digital signals corresponding to the first and secondsub-bands. According to an exemplary embodiment, first and second A/Dconverters 40 and 50 generate the digital signals at step 330 bydigitizing the signals provided from HPF 20 and LPF 30, respectively. Inthis manner, first A/D converter 40 generates digital signalscorresponding to the first sub-band, while second A/D converter 50generates digital signals corresponding to the second sub-band.

At step 340, multi-channel satellite signal receiving apparatus 100/200processes the digital signals generated at step 330 to thereby generatea plurality of digitally processed signal streams in a simultaneousmanner. According to an exemplary embodiment, DSP tuners 60 process thedigital signals at step 340 by performing various processing functionsincluding digital tuning (e.g., multi-channel frequency downconversion),digital filtering, decimation, digital demodulation (e.g., QPSK, QAM,and/or other types of demodulation), and FEC decoding functions. Aspreviously indicated herein, each of the digitally processed signalstreams generated by DSP tuners 60 corresponds to a given transponder,and may include a plurality of time-division multiplexed broadcastprograms.

At step 350, multi-channel satellite signal receiving apparatus 100/200provides a plurality of digital transport streams in a simultaneousmanner. According to an exemplary embodiment, transport processor 70demultiplexes the digitally processed signal streams provided from DSPtuners 60 to thereby provide the plurality of digital transport streamsin a simultaneous manner at step 350. As previously indicated herein,each of the digital transport streams provided from transport processor70 may include a broadcast program. In this manner, broadcast programsfrom both the first and second sets of transponders may be accessed in asimultaneous manner.

As described herein, the present invention provides a multi-channelsatellite signal receiving apparatus which is capable of simultaneouslyproviding broadcast programs from a plurality of different sets oftransponders in a satellite broadcast system. While this invention hasbeen described as having a preferred design, the present invention canbe further modified within the spirit and scope of this disclosure. Thisapplication is therefore intended to cover any variations, uses, oradaptations of the invention using its general principles. Further, thisapplication is intended to cover such departures from the presentdisclosure as come within known or customary practice in the art towhich this invention pertains and which fall within the limits of theappended claims.

1. A multi-channel satellite signal receiving apparatus, comprising:input means for receiving input signals via a single cable from apredetermined frequency band having a first sub-band and a secondsub-band, said first sub-band including first signals which previouslyexhibited a first polarization provided from a first set oftransponders, and said second sub-band including second signals whichpreviously exhibited a second polarization provided from a second set oftransponders; and processing means for simultaneously providing aplurality of digital transport streams corresponding to said first andsecond sets of transponders responsive to said first and second signals.2. The multi-channel satellite signal receiving apparatus of claim 1,wherein each of said digital transport streams includes a broadcastprogram.
 3. The multi-channel satellite signal receiving apparatus ofclaim 1, wherein: said first sub-band is approximately 950 to 1450 MHz;and said second sub-band is approximately 1650 to 2150 MHz.
 4. Themulti-channel satellite signal receiving apparatus of claim 1, wherein:said first set of transponders includes odd numbered transponders; andsaid second set of transponders includes even numbered transponders. 5.The multi-channel satellite signal receiving apparatus of claim 1,wherein said processing means includes filtering means for separatingsaid first and second sub-bands.
 6. The multi-channel satellite signalreceiving apparatus of claim 5, wherein said filtering means includes ahigh pass filter and a low pass filter.
 7. The multi-channel satellitesignal receiving apparatus of claim 1, wherein said processing meansincludes: first analog-to-digital converting means for performing afirst analog-to-digital conversion; second analog-to-digital convertingmeans for performing a second analog-to-digital conversion; and whereina common clock controls said first and second analog-to-digitalconverting means.
 8. The multi-channel satellite signal receivingapparatus of claim 7, wherein said common clock exhibits a frequencybetween said first and second sub-bands.
 9. A method for operating amulti-channel satellite signal receiving apparatus, comprising steps of:receiving input signals via a single cable from a predeterminedfrequency band having a first sub-band and a second sub-band, said firstsub-band including first signals which previously exhibited a firstpolarization provided from a first set of transponders, and said secondsub-band including second signals which previously exhibited a secondpolarization provided from a second set of transponders; and processingsaid first and second signals to simultaneously provide a plurality ofdigital transport streams corresponding to said first and second sets oftransponders.
 10. The method of claim 9, wherein each of said digitaltransport streams includes a broadcast program.
 11. The method of claim9, wherein: said first sub-band is approximately 950 to 1450 MHz; andsaid second sub-band is approximately 1650 to 2150 MHz.
 12. The methodof claim 9, wherein: said first set of transponders includes oddnumbered transponders; and said second set of transponders includes evennumbered transponders.
 13. The method of claim 9, wherein saidprocessing step includes a filtering operation for separating said firstand second sub-bands.
 14. The method of claim 13, wherein said filteringoperation includes a high pass filtering operation and a low passfiltering operation.
 15. The method of claim 9, wherein said processingstep includes: performing a first analog-to-digital conversion;performing a second analog-to-digital conversion; and wherein a commonclock controls said first and second analog-to-digital conversions. 16.The method of claim 15, wherein said common clock exhibits a frequencybetween said first and second sub-bands.
 17. A multi-channel satellitesignal receiving apparatus comprising: an input (10) operative toreceive input signals via a single cable from a predetermined frequencyband having a first sub-band and a second sub-band, said first sub-bandincluding first signals which previously exhibited a first polarizationprovided from a first set of transponders, and said second sub-bandincluding second signals which previously exhibited a secondpolarization provided from a second set of transponders; and signalprocessing circuitry operative to simultaneously provide a plurality ofdigital transport streams corresponding to said first and second sets oftransponders responsive to said first and second signals.
 18. Themulti-channel satellite signal receiving apparatus of claim 17, whereineach of said digital transport streams includes a broadcast program. 19.The multi-channel satellite signal receiving apparatus of claim 17,wherein: said first sub-band is approximately 950 to 1450 MHz; and saidsecond sub-band is approximately 1650 to 2150 MHz.
 20. The multi-channelsatellite signal receiving apparatus of claim 17, wherein: said firstset of transponders includes odd numbered transponders; and said secondset of transponders includes even numbered transponders.
 21. Themulti-channel satellite signal receiving apparatus of claim 17, whereinsaid signal processing circuitry includes filtering circuitry operativeto separate said first and second sub-bands.
 22. The multi-channelsatellite signal receiving apparatus of claim 21, wherein said filteringcircuitry includes a high pass filter and a low pass filter.
 23. Themulti-channel satellite signal receiving apparatus of claim 17, whereinsaid signal processing circuitry includes: a first analog-to-digitalconverter operative to perform a first analog-to-digital conversion; asecond analog-to-digital converter operative to perform a secondanalog-to-digital conversion; and wherein a common clock controls saidfirst and second analog-to-digital converters.
 24. The multi-channelsatellite signal receiving apparatus of claim 23, wherein said commonclock exhibits a frequency between said first and second sub-bands.